https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80454
Marek Polacek <mpolacek at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mpolacek at gcc dot gnu.org --- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Is this really a bug? In the second case we have a union in two nested structs, in the first case just two nested structs. clang also warns: w.c:3:60: warning: suggest braces around initialization of subobject [-Wmissing-braces] struct { struct { union_t a; long b; } x; int y; } u = { { 0 }, 1 }; ^ {} But yes, the fix-it hints looks strange.